I've got one due tomorrow or Saturday and there is no doubt that she is in pig - it's been very obvious for a couple of weeks.
As HappyHippy said, moving a sow soon after service is risky. It either has to be within a few days of service or a good month later, to ensure the embryos have implanted. Also, a responsible breeder will hang onto a sow or gilt to be sure she doesn't come back into season before allowing her to be sold.
You may have a nice surprise - in which case, get her into her farrowing quarters and get everything ready. If not, good luck for next time. Should she not be in pig this time, I doubt whether you'd get much joy. His argument could be that he believed she was in pig, but she could have lost them due to the move.
Either way, good luck, and if it doesn't happen, just put it down to experience x